RU2420668C1 - Double-flow gas turbine engine - Google Patents

Abstract

FIELD: engines and pumps. ^ SUBSTANCE: double-flow gas turbine engine includes high pressure compressor, annular supply header, inter-labyrinth cavity adjacent to side surface of peripheral part of disc of high pressure turbine, which is separated from flow part of turbine with labyrinth seal, with inter-disc cavity separated from inter-labyrinth cavity with labyrinth seal and interconnected with flow part of turbine through cavity of slot channel in the area of peripheral part of disc of low pressure turbine. Compressor cavity is connected through the channel passing through inner cavities of blades of LP turbine nozzle diaphragm. Inter-disc cavity is divided into discharge cavity of HP turbine, discharge cavity of LP turbine, which are separated from each other with a wall fixed along outer diametre on nozzle diaphragm of LP turbine and labyrinth seal on the side of inner diametre of wall and cavity of slot channel, which is separated from discharge cavity of LP turbine with labyrinth seal. Discharge cavity of HP turbine is connected to cavity of slot channels with transit tubes. Discharge cavity of LP turbine is interconnected with annular supply header through channels. ^ EFFECT: invention provides the change and adjustment of axial forces acting on turbine rotors. ^ 9 cl, 4 dwg

Description

The invention relates to a cooling system for a gas turbine engine (GTE), and in particular to cooling an interdisc space of a turbine with air taken from a compressor.

Known double-circuit gas turbine engine, containing a high-pressure compressor, the dummy cavity of which is connected through a channel passing through the internal cavity of the blades of the nozzle apparatus of the low-pressure turbine, an annular feed manifold, an inter-labyrinth cavity adjacent to the peripheral part of the disk of the high-pressure turbine, separated from the turbine flow part labyrinth seal, with an interdisc cavity, separated from the interlabyrinth cavity, a labyrinth seal and in communication with the turbine flow through the cavity of the slotted duct in the region of the peripheral part of the disk of the low pressure turbine (see RF patent No. 2200859, IPC F02C 7/12, publ. 2003).

The great advantages of such an engine include the utilization of Dumis air and its use for cooling the interdisk cavity of the turbine, as a result of which the cooling air cools the side surfaces of the high and low pressure turbine disks and is not emitted into the atmosphere, but flows into the turbine flow path, increasing the engine efficiency.

However, the release of cooling air from the dumis cavity into the interdisk cavity disrupts the balance of axial forces acting on the rotors of the high and low pressure turbines, which leads to a change in the forces acting on angular contact bearings and, consequently, to a reduction in their service life and their more frequent replacement , which is impossible without disassembling the engine. To bring the axial forces acting on the rotors of the high and low pressure turbines to normal, the diameter of the labyrinth seals on the turbine rotors must be changed, which is a serious alteration of the design, since part of the labyrinths is made in conjunction with the disks. Such alterations are possible both at the beginning of mass production and the refinement of engine production technology, and during the development of various modifications of this engine.

The objective of the invention is not only to compensate for the effect of the supply of dumis air supplied to the interdisk cavity of the turbine on the magnitude of the axial forces acting on the rotors of the turbines, and hence on the angular contact bearings of the engine mounts, but also to provide the ability to change and adjust these forces, which is especially important when fine-tuning the engine and when working on engine modifications that differ from each other in their parameters, such as traction.

This problem is achieved in that in a double-circuit gas turbine engine containing a high-pressure compressor, the dummy cavity of which is connected through a channel passing through the internal cavities of the blades of the nozzle apparatus of the low-pressure turbine, an annular feed manifold, an interlabyrinth cavity adjacent to the side surface of the peripheral part of the high-pressure turbine disk separated from the turbine flow through a labyrinth seal, with an interdisc cavity separated from the interlabyrinth cavity by a labyrinth seal and communicated with the turbine flow part through the slotted duct cavity in the region of the peripheral part of the low pressure turbine disk, in it the interdisk cavity is divided into the unloading cavity of the high pressure turbine, the unloading cavity of the low pressure turbine, separated from each other by a wall fixed along the outer diameter to the turbine nozzle apparatus low pressure and labyrinth seal on the side of the inner diameter of the wall and the cavity of the slotted duct, separated from the discharge cavity of the low pressure turbine by the labyrinth seals. In this case, the discharge cavity of the high pressure turbine is connected to the cavity of the slotted duct by transit tubes, and the discharge cavity of the low pressure turbine is in communication with the annular feed manifold channels.

In addition, it is possible that:

- the ends of the transit tubes are rigidly fixed to the wall separating the discharge cavities of the high and low pressure turbines, and to the inner body of the nozzle apparatus by welding or soldering;

- transit tubes are made curved;

- transit tubes are equipped with calibrated sections;

- calibrated sections of the transit tubes are placed on the side of the cavity of the slotted duct and are made in the form of removable jets;

- part of the transit tubes from the side of the cavity of the slotted duct is equipped with removable plugs;

- channels connecting the discharge cavity of the low pressure turbine with the supply manifold are provided with calibrated sections;

- calibrated sections of the channels connecting the discharge cavity of the low pressure turbine with the supply manifold, made in the form of removable nozzles;

- part of the channels connecting the discharge cavity of the low pressure turbine with the supply manifold is equipped with plugs.

The separation of the interdisc cavity into the discharge cavity of the high-pressure turbine, the discharge cavity of the low-pressure turbine and the cavity of the slotted duct, separated from the discharge cavity of the low-pressure turbine by a labyrinth seal, makes it possible to obtain three cavities isolated from each other, the air pressures of which act on the side surfaces of the turbine disks as high and low pressures, which makes it possible to have different air pressures in these cavities, and therefore affect the turbine disks in different ways Exposure to extreme pressure and low pressure. As a result, it becomes possible to affect both turbine rotors with different axial loads.

The connection of the discharge cavity of the high-pressure turbine with the cavity of the slotted duct by transit tubes allows one to change the pressure in it from a relatively high pressure of the labyrinth cavity (adjusted for the pressure drop across the labyrinth seal) to a relatively low pressure of the cavity of the slotted duct, varying the area of the passage section of the transit tubes.

Rigid fastening of the ends of the tubes on the wall separating the discharge cavities of the high and low pressure turbines and on the inner casing of the nozzle apparatus by welding or soldering allows the transit tubes to perform a power function in addition to their direct function, reinforcing the wall separating the discharge cavities in the force relation high and low pressure turbines.

The connection of the discharge cavity of the low pressure turbine with the annular feed manifold channels allows you to change the pressure in the discharge cavity of the low pressure turbine, practically, from a relatively high pressure in the cavity of the annular feed manifold to a relatively low pressure of the slotted duct cavity (adjusted for the differential pressure across the labyrinth seal), varying the area of the channels.

The execution of the transit tubes curved allows you to change their rigidity and ductility along the longitudinal axis of the engine.

The implementation of calibrated sections on transit tubes allows you to clearly change the area of the tube cross section, which, in turn, allows you to adjust the pressure in the discharge cavity of the high pressure turbine.

The implementation of the calibrated sections of the transit tubes from the side of the cavity of the slotted duct in the form of removable jets allows you to perform the necessary pressure adjustment in the discharge cavity of the high pressure turbine without disassembling the nozzle apparatus of the low pressure turbine.

The execution of part of the transit tubes from the side of the cavity of the slotted duct with removable plugs allows you to perform even deeper pressure control in the discharge cavity of the high pressure turbine without disassembling the nozzle apparatus of the low pressure turbine.

The supply of channels connecting the discharge cavity of the low pressure turbine with the supply manifold, calibrated sections allows you to accurately control the pressure in the discharge cavity of the low pressure turbine.

The implementation of the calibrated sections of the channels connecting the discharge cavity of the low pressure turbine with the supply manifold, in the form of removable nozzles, allows you to perform the necessary pressure adjustment in the discharge cavity of the low pressure turbine without disassembling the nozzle apparatus of the low pressure turbine.

Providing part of the channels connecting the discharge cavity of the low pressure turbine with the supply manifold with plugs allows even deeper adjustment of the pressure in the discharge cavity of the low pressure turbine without disassembling the nozzle apparatus of the low pressure turbine.

Figure 1 shows a longitudinal section of a double-circuit gas turbine engine.

Figure 2 shows a longitudinal section of a turbine engine.

Figure 3 shows a longitudinal section of a turbine engine with plugs on transit tubes.

Figure 4 shows a longitudinal section of a turbine engine with calibrated sections on transit tubes.

The double-circuit gas turbine engine contains a high-pressure compressor 1, the dummy cavity 2 of which is connected through a channel 3, passing through the heat exchanger 4, the internal cavities 5 of the blades 6 of the nozzle apparatus 7 of the low-pressure turbine 8, the annular feed manifold 9, the inter-labyrinth cavity 10 adjacent to the peripheral side surface 11 part of the disk 12 of the high pressure turbine 13, separated from the flow part of the turbine 14 by the labyrinth seal 15, with the interdisc cavity 16, separated from the interlabyrinth cavity 10 by the labyrinth seal 17 and communicated with the flow part of the turbine 14 through the cavity of the slotted duct 18 in the region of the peripheral part of the disk 19 of the low pressure turbine 8. The interdisc cavity 16 is divided into the discharge cavity 20 of the high pressure turbine 13, the discharge cavity 21 of the low pressure turbine 8, separated from each other a wall 22 fixed on the outer diameter of the nozzle apparatus 7 of the low-pressure turbine 8 and a labyrinth seal 23 on the side of the inner diameter of the wall 22 and the cavity of the slotted duct 18, separated from the discharge cavity 21 low pressure turbines 8 with a labyrinth seal 24, while the discharge cavity 20 of the high pressure turbine 13 is connected to the cavity of the slotted duct 18 by transit tubes 25, and the discharge cavity 21 of the low pressure turbine 8 is in communication with the annular supply manifold 9 channels 26.

The transit tubes 25 are made curved, their ends are rigidly fixed on the wall 22 separating the discharge cavities 20 and 21, and on the inner housing 27 of the nozzle apparatus 7 by welding or soldering and provided with calibrated sections 28 from the side of the cavity of the slotted duct 18 and which can be removable . Part of the transit tubes 25 from the side of the cavity of the slit duct 18 can be equipped with removable plugs 29. The channels 26 connecting the discharge cavity 21 of the low pressure turbine 8 with the supply manifold 9 are provided with calibrated sections 30. Some of the channels 26 can be equipped with plugs 31.

The heat exchanger 4 is installed in the second circuit 32 of the gas turbine engine. The interdisc cavity 16 is limited on the inner diameter side by a labyrinth seal 33 mounted between the rotors of the high 13 and low 8 pressure turbines. The dumis cavity 2 is separated from the flow part of the high-pressure compressor 34 by a labyrinth seal 35. A combustion chamber 36 is located in the engine between the high-pressure compressor 1 and the high-pressure turbine 13. The labyrinth seal 33 separates the internal cavities 37 of the turbine from the interdisc space 16. Calibrated sections 30 and 28 can be made in the form of removable jets 38 and 39.

The device operates as follows.

Air from the dumis cavity 2 of the high-pressure compressor 1 through the channel 3 passing through the air-air heat exchanger 4, the internal cavity 5 of the blades 6 of the nozzle apparatus 7, enters the annular feed manifold 9, from which, on the one hand, enters the inter-labyrinth cavity 10, from where it goes through the labyrinth seal 15 to the flow part of the turbine 14, and simultaneously through the labyrinth seal 17 it enters the discharge cavity 20 of the high pressure turbine 13, from which through transit tubes 25 with calibrated sections 28 goes into the cavity of the slotted duct 18 and then into the flow part of the turbine 14.

On the other hand, air from the supply annular manifold 9 through the channels 26 enters the discharge cavity 21 of the low pressure turbine 8, and leaves it through the labyrinth seal 24 into the cavity of the slotted duct 18, and the rest through the labyrinth seal 23 is directed to the discharge cavity 20 of the turbine high pressure 13, and together with the air entering through the labyrinth seal 17, is evacuated through transit tubes 25 into the cavity of the slotted duct 18 and then into the flowing part of the turbine 14.

The calibrated sections 28 and 30 allow you to adjust the passage area of the air channels and, thus, change the pressure level in the discharge cavities 20 and 21.

By reducing the area of the calibrated sections 28 up to complete overlap, the pressure in the discharge cavity 20 of the high pressure turbine 13 increases, and thereby the axial load of the high pressure turbine 13 decreases and the axial load on the angular contact bearing of the high pressure rotor of the engine increases.

When the area of the calibrated sections 30 is reduced to a small flow rate through the labyrinth seal 24, constructed from the condition of preventing the backflow of the gas-air mixture from the cavity of the slotted duct 18 into the discharge cavity 21 of the low pressure turbine 8, the axial load of the low pressure turbine 8 decreases, and the load on the angular contact the low pressure rotor bearing of the engine is increasing.

The presence of two autonomous discharge cavities of the turbines, separated by a wall 22 and two autonomous calibrated sections 28 and 30, allows you to change the level of axial loads of the rotors of the engine simultaneously or separately and in a wide range in size.

This circumstance allows us to adjust these loads for the necessary durability and resource of the engine during the development and refinement of the engine, without changing the design and layout of the engine, at the stage of fine-tuning the engine according to axial loads. This significantly reduces the cost and timing of engine refinement.

Using removable jets 38 and 39, as well as removable plugs 31 and 29, the axial load on the rotor of the turbines 8 and 13 can be adjusted smoothly.

When implementing the invention, a mixed variant is possible, when at the same time removable plugs are placed on part of the ducts, and removable jets on the other part.

Installing only removable plugs significantly reduces the process of adjusting for axial load, but is fraught with a spasmodic change in axial load - which is not always acceptable.

Claims (9)

1. A double-circuit gas turbine engine containing a high-pressure compressor, the dummy cavity of which is connected through a channel passing through the internal cavities of the blades of the nozzle apparatus of the low-pressure turbine, an annular feed manifold, an inter-labyrinth cavity adjacent to the side surface of the peripheral part of the high-pressure turbine disk, separated from the flow turbine parts with a labyrinth seal, with an interdisc cavity separated from the interlabyrinth cavity by a labyrinth seal and communicated with the flowing part the turbine through the cavity of the slotted duct in the region of the peripheral part of the disk of the low pressure turbine, characterized in that the interdisk cavity is divided into the discharge cavity of the high pressure turbine, the discharge cavity of the low pressure turbine separated by a wall fixed to the outer diameter of the nozzle apparatus of the low turbine pressure and labyrinth seal on the side of the inner diameter of the wall and the cavity of the slotted duct, separated from the discharge cavity of the low pressure turbine by the labyrinth densification, while the discharge cavity of the high pressure turbine is connected to the cavity of the slotted duct by transit tubes, and the discharge cavity of the low pressure turbine is in communication with the annular feed manifold channels. 2. The double-circuit gas turbine engine according to claim 1, characterized in that the ends of the transit tubes are rigidly fixed to the wall separating the discharge cavities of the high and low pressure turbines and to the inner nozzle apparatus by welding or soldering, 3. The dual-circuit gas turbine engine according to claim 2, characterized in that the transit tubes are made curved. 4. The dual-circuit gas turbine engine according to claim 1, characterized in that the transit tubes are equipped with calibrated sections. 5. The dual-circuit gas turbine engine according to claim 4, characterized in that the calibrated sections of the transit tubes are located on the side of the slotted duct cavity and are made in the form of removable jets. 6. The dual-circuit gas turbine engine according to claim 1, characterized in that part of the transit tubes from the side of the cavity of the slotted duct is equipped with removable plugs. 7. The double-circuit gas turbine engine according to claim 1, characterized in that the channels connecting the discharge cavity of the low pressure turbine to the supply manifold are provided with calibrated sections. 8. The dual-circuit gas turbine engine according to claim 7, characterized in that the calibrated sections of the channels connecting the discharge cavity of the low pressure turbine to the supply manifold are made in the form of removable jets. 9. The double-circuit gas turbine engine according to claim 1, characterized in that part of the channels connecting the discharge cavity of the low pressure turbine to the supply manifold is provided with plugs.

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